Look in your manual page 41
Identification
The identification screens display the following UPS information:
Type and model
Part number
Serial number
UPS firmware
Network Management Card firmware
NOTE:
The NMC firmware screen displays only if the Network Management Card is installed. See “Dell
Network Management Card“ on page 56
This seems to be from the ups screen not the managing software I would make sure that Network Management Card firmware appears to make sure the UPS is aware of the network card.
The Network Management card manual is separate form the UPS
ftp://ftp.dell.com/Manuals/all-products/esuprt_ser_stor_net/esuprt_rack_infrastructure/dell-line-interactive-rack-ups-2700r_User%27s%20Guide14_en-us.pdf
According to this the network card has a serial port somewhere, so you need a laptop with a serial port (obsolete port on laptops nowadays but a usb-to-serial is handy to be around)
you should be connecting to that port and getting access to a console based menu where you configure your card settings.
P.S: You might find PuTTy handy since applications like hyperterminal are also obsolete
http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html
Make sure you connect to "Serial" and type in the COM port of your serial card (i.e COM1)